Lamp-socket.



G. G. KNAUFP.

LAMP socxm. APPLICATION FILED JAN. 13, 1913.

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APPLICATION PILEIP JAN. 13,1913.

1,106,459. Patented Aug. 11,1914.

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GEORGE G. KNAUFF, OF CHICAGO, ILLINOIS.

LAMP-SOCKET.

mortise.

Specification. of Letters Patent.

Application filed January 13, 1913. Serial No. 741,767.

To all whom it may concern:

Be it known that I, GEORGE C. KNAUFF, citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Lamp-Sockets; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates'to sockets for. electric lamps and particularly to the class of sockets used for thehead and tail lamps of automobiles. It has been customary heretofore to build sockets for this class of lamps with shells having bayonet-catch slots adapted to engage laterally projecting pins upon the lamp bases, each lamp having a pair of contacts adapted to contact with "spring-pressed terminals mounted within the socket. In practice, the spring-actuated terminals have not always been found dependable as giving good contacts while the exceedingly small springs and p ungers re quired for such spring terminals have 'proven liable to get out of order.-

The object of my invention is to provide a socket in which the terminals. may be rigidly secured to the socket, and in which the shell-or casing with which the lamp base interlocks will be spring-actuated so as to compensate for variations in the coactin'g terminals of the lamp and socket; also one in which an interlocking engagement between the lamp and shell may be used with a socket havin a grounded casing and a single insulated terminal.

Other objects will appear from thefollowing description and from the drawings, in which: o

Figure --1 is a view, partly 1n section, of a socket embodying my invention and of a lamp interengaged with this socket. Figs.

-2- and 3 are sections through Fig. 1 along the lines 2-2 and 33. Fig. 4 is an elevation of the sliding casing forming part of the socket of Fig. -1.

Fig. 5- is a plan viewof the insulating member of Fig. -1, with the terminals attached thereto. Figs. 6, 7 and 8 show alternative embodiments of my invention. In the embodiment shown in Fig. 1

the socket of my invention has an insulating body 1 mounted immovably in a casing or shell 2, which casing is threaded to match threads in the metal body 3 of an automobile lamp or lantern. Secured to the insulating body 1 and insulated from each. other are socket terminals 4 and 5, the

former of which is adapted to receive a Patented Aug. 11, 1914:.

wire G While thelatter is grounded to the casing 2 and hence to the base 3 of the lamp body. The upper ends of the terminals l and 5 are' adapted to contact with lamp dimetrically'opposed projections 11 and 12 upon the same. Theeasing 2 preferably has both ends flared inwardly, whereby the lower end is "adapted to engage the body 1, while the upper end.13 serves as a guide for an inner shell 14 which is adapted to slide 'longitudinally of the casing 1. This slidable shell 14 has oppositely disposed slots 15 leading downward to inclined slots 16, the latter terminating in upwardly directed pockets 17. At the lower end of the shell 14 the latter is flared out to provide a flanged portion 18, this flange having oppositely disposed extensions 19 and 20 adapted to project through longitudinal slots 21 and 22 in the casing 2. A spiral compression spring 23 interposed between the casing 2 and the slidable shell 14: bears at its opposite ends against the flange 18 and the inwardly turned end 13 of the main casing, thereby forcing the sliding shell or auxiliary casing 14 downwardly or toward the insulating body 1 of the socket, while the extensions 19 and 20 prevent the said sliding shell from rotating with reference to the casing and body of the socket.

In using the socket of Figs. -1-, 2, -3- and 4,.the lamp 9 is inserted with the projections 11 and 12 entering the vertical slots 15 in the slidableshell 14 until these projections strike the inclined continuations 16 of the said slots, at which time the exterminals 6' and 7 mounted upon the ina the extreme end of the lamp base) will abut against portions of the body member which latter consists of the insulating body 1 and the terminals carried thereby. Then on rotating the lamp, the projections upon its base will engage the upper edges of the inclined slot portions 16 and, since the shell 14 is prevented from rotation by the engagement of the projecting tips 19 and 20 with the slots 21 and 22, the edges of the said inclined slots will act as cam surfaces for forcing the shell 14 upward against the pressure of the spring 23 as the lamp is rotated. This upward motion continues until the projections 11 and 12 seat in the notches 17, thereby interlocking the lamp base with the coacting formations upon the slidin shell 14. When the lamp and the lampk-hol ing member 14 are thus interengaged, the lamp terminals 6 and 7 will be'in alinement with the socket terminals 1 and 5, and will be pressed into firm contact with the latter through the action of the spring 23. Consequently, this spring will simultaneously hold the "lamp firmly interlocked with the socket and in.

good contacting relation with the terminals of the latter. "Should the contacting terminals on either the lamp, or the socket (as in Fig. 8), or both, be uneven in length, the spring-held slidable shell 14 may tilt as in Fig. 8 so as'to permit of proper contacting between the coacting terminals. Instead of electrically connecting or grounding one of the socket terminals to the shell of the socket and thereby sto the metallic parts supporting the socket, both terminals may be insulated from the socket casing, as in Fig. 7-. It will be obvious that in order to obtain the effective action of the spring interposed between the main casing and the auxiliary casing which is slidably and non-rotatably carried thereby, the distance between the lateral-projections upon the lamp base and the extreme end of the latter must be greater than the normaldistance between the socket formations or notches 17 and the uppermost parts of the 1 body member. Moreover, it will be evident that when the base of the lamp is inserted in the auxiliary casing, it will enter with its terminals out of alinement with the socket terminals; so that thelamp terminals will abut against insulatin portions o'fthe body member, but will be rought into abutting relations with the socket terminals when the lamp is rotated to effect the interlocking of the projections upon its base with the said notches or sockets of the slot formations in the auxiliary casing. The socket of my invention may also be used with lamp-bases having a single centrally positioned endward terminal, the other terminal being grounded to the metal shell of the lamp base. In this case, the sliding part of the socket casing need not be locked against rotation, but may be grasped by an outer bead 31, as in Fig. -6, for holding the casing non-rotatably while the lamp is being inserted.

While I preferably equip one portion of the socket casing with inclined slots adapted to provide cam surfaces for moving this part of the casingagainst the pressure of the spring and thereby permitting the projections on the lamp base to reach the pockets 17, these inclined portions of the slots may be omitted as in Fig. 7. The latter shows a socket inwhich the pockets 17 directly adjoin the vertical slots'15, access to the pockets being had by manually separating the two parts of the socket casing, for which purpose the inner shell may be grasped by the projecting bead 31.

Having thus shown and described my invention in an embodiment capable of many modifications without departing ,from the spirit of my invention, I claim' 1. In a socket for a lamp having a lateral projection and an axially disposed filament terminal upon its base, an insulating body, a-wire terminal carried thereby; a main casing housing the insulating'body and having a contracted end projecting beyond the insulating body; an auxiliary casing slidably v mounted within the said projecting portion of the main casing and extending beyond the said contracted end, the said auxiliary casing receiving the base of the said lamp and equipped with slots admitting the said projections respectively, each of said slotshaving a notch at its inner end, the said, notches respectively interengaging the said projections toeouple the lamp to the socket, the said terminals abutting against each other when the lamp is thus coupled to the socket; the inner end of the auxiliary casing" being flared outwardly; and a compression spring interposed between the said casings by the main casing and receiving the base of the lamp with the said lamp and wire terminals abutting against each other, there being upon the auxiliary casing slot formations admitting the said projections upon the lamp base when the said base is receix'ml by the. auxiliary casing, the said slot formations terminating in notches intereugaging with the said projections to couple the-lamp abutting surfaceof the said Wire terminal and the said notches.

3. In a socket for a lamp having lateralprojections and an exposed terminal upon its base, an insulating body, a wlre terminal and a main casing both carried by the insulating body; an auxiliary casing slidably carried by the main casing and receiving the base of the lamp, the said lamp and wire terminals abutting against each other when the lamp base is thus received by the auxiliary casing; the said main and auxiliary casings being equipped with coacting formations to prevent relative rotation thereof; there being upon the auxiliary casing slot formations admitting thesaid projections upon the lamp base when the said base is received by the auxiliary casing, the said slot formations terminating in notches; each of the said slots having a downwardly inclined portion, walls of the said inclined portions presenting cam surfaces coacting with the said projections and with the said abutting of the terminals upon rotation of the lamp relative to the casing to slide theauxiliary .casing with respect to the main casing to permit the projections to be brought into interengagement with the said notches of the slot formations, thereby coupling the lamp with the socke 4. In a socket for a lamp having a lateral projection and an axially disposed filament terminal upon its base, an insulating body,

' a wire terminal carried thereby; a main casing housing the insulating body and having a contracted end projecting beyond the insulating body; an auxiliary casing slidably mounted Within the said projecting portion of the main casing and extending beyond the latter, the said auxiliary casing receiving the base of the said lamp and equipped with slots admitting the said projections respectively, each of said slots having a notch at its inner end and a downwardly inclined portion leading thereto; the inner end of the auxiliary casing being flared outwardly;

and a spring interposed bet-ween the saidv casings and abutting at its respective ends against the flared portion of the auxilia casing and'against the contracted end of the main casing. the said spring opposing a.

relative sliding motion of the said casings; walls of the said inclined slot portions affording cam surfaces coacting with the said projections upon 'rotation of the lamp rela-- tive to the auxiliary casing to slide the latter relative to the main casing against the pressure of the said spring to permit the projections to be interlocked with the said notches of the slots.

5. In a socket for a lamp having lateral projections upon its base and having the ends of its filament connected respectively to a metallic shell and an axially disposed contact carried by the said base, a main casing connected to one terminal of a circuit; an insulating body mounted in said casing; an axially disposed wire terminal carried by the said insulating body and connected to the other terminal of the circuit; an auxiliary casing slidably mounted Within the main casing and slidably fitting the said metallic shell upon the lamp base; and a compression spring interposed between the said casings and abutting at its ends respectively against a portion of each casing to oppose a relative sliding motion of the casings; there being-in the auxiliary casing slots admitting the said projections upon the lamp base when the latteris inserted in the auxiliary casing with the said axially disposed terminals abutting against each other; the said slots including inclined portions terminating in'notches, walls of the said inclined portions presenting cam surfaces coacting with the said projections and with the said abutting of the axially disposed terminals upon rotation of the lamp relative to the auxiliary casing to slide the latter with respect to the main casing against the. pressure of the said spring, thereby permitting the projections to be brought into interengagement with the said notches to efiect a coupling of the lamp with the socket.

6. In a socket for a lamp having lateral projections upon its base and having the ends of its filament connected respectively to a metallic shell and an axially disposed contact carried by the said base, a main casing connected to-one terminal of a circuit; an insulating body mounted in the said casing; an axially disposed wire terminal carried by the said insulating body and connected to the other terminal of the circuit; an auxiliary casing slidably mounted Within the main casing and slidably fitting the said metallic shell upon the lamp base, there being cooperating formations upon the said casings to prevent relative rotation of the latter; and a compression spring interposed between the said casings and abutting at its ends respectively against a portion of each casing to oppose a relative sliding motion of the said casings; there being in the auxiliary casing slots admitting the said projections upon the lamp base when the latter is inserted in the auxiliary casing with the said axially disposed terminals abutting against each other; the said slots including inclined portions terminating in notches, walls of the said inclined portions presenting cam surfaces coacting.\vit-h the said projections and with the said abutting of the axially disposed terminals upon rotation of the lamp relative to the casings to slide the auxiliary casing with respect to the main 7 casing against the pressure of the said spring, thereby permitting the projections to be brought into interengagement with the said notches to effect a coupling of the lamp with 10 the socket. y In testimony whereof I have signed my name in presence of two subscribing witnesses.

GEORGE C. KNAUFE. Witnesses; ALBERT SCH'EIBLE,

RUDOLPH WM.'LOTZ. 

